/*******************************************************************************
* Copyright (c) 2000, 2015 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jface.preference;
import org.eclipse.swt.SWT;
import org.eclipse.swt.accessibility.AccessibleAdapter;
import org.eclipse.swt.accessibility.AccessibleEvent;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.ColorDialog;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import static org.eclipse.swt.events.SelectionListener.widgetSelectedAdapter;
import org.eclipse.core.commands.common.EventManager;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
/**
* The <code>ColorSelector</code> is a wrapper for a button that displays a
* selected <code>Color</code> and allows the user to change the selection.
*/
public class ColorSelector extends EventManager {
/**
* Property name that signifies the selected color of this
* <code>ColorSelector</code> has changed.
*
* @since 3.0
*/
public static final String PROP_COLORCHANGE = "colorValue"; //$NON-NLS-1$
private Button fButton;
private Color fColor;
private RGB fColorValue;
private Point fExtent;
private Image fImage;
/**
* Create a new instance of the reciever and the button that it wrappers in
* the supplied parent <code>Composite</code>.
*
* @param parent
* The parent of the button.
*/
public ColorSelector(Composite parent) {
fButton = new Button(parent, SWT.PUSH);
fExtent = computeImageSize(parent);
fImage = new Image(parent.getDisplay(), fExtent.x, fExtent.y);
GC gc = new GC(fImage);
gc.setBackground(fButton.getBackground());
gc.fillRectangle(0, 0, fExtent.x, fExtent.y);
gc.dispose();
fButton.setImage(fImage);
fButton.addSelectionListener(widgetSelectedAdapter(event -> open()));
fButton.addDisposeListener(event -> {
if (fImage != null) {
fImage.dispose();
fImage = null;
}
if (fColor != null) {
fColor.dispose();
fColor = null;
}
});
fButton.getAccessible().addAccessibleListener(new AccessibleAdapter() {
@Override
public void getName(AccessibleEvent e) {
e.result = JFaceResources.getString("ColorSelector.Name"); //$NON-NLS-1$
}
});
}
/**
* Adds a property change listener to this <code>ColorSelector</code>.
* Events are fired when the color in the control changes via the user
* clicking an selecting a new one in the color dialog. No event is fired in
* the case where <code>setColorValue(RGB)</code> is invoked.
*
* @param listener
* a property change listener
* @since 3.0
*/
public void addListener(IPropertyChangeListener listener) {
addListenerObject(listener);
}
/**
* Compute the size of the image to be displayed.
*
* @param window -
* the window used to calculate
* @return <code>Point</code>
*/
private Point computeImageSize(Control window) {
GC gc = new GC(window);
Font f = JFaceResources.getFontRegistry().get(
JFaceResources.DIALOG_FONT);
gc.setFont(f);
int height = gc.getFontMetrics().getHeight();
gc.dispose();
Point p = new Point(height * 3 - 6, height);
return p;
}
/**
* Get the button control being wrappered by the selector.
*
* @return <code>Button</code>
*/
public Button getButton() {
return fButton;
}
/**
* Return the currently displayed color.
*
* @return <code>RGB</code>
*/
public RGB getColorValue() {
return fColorValue;
}
/**
* Removes the given listener from this <code>ColorSelector</code>. Has
* no effect if the listener is not registered.
*
* @param listener
* a property change listener
* @since 3.0
*/
public void removeListener(IPropertyChangeListener listener) {
removeListenerObject(listener);
}
/**
* Set the current color value and update the control.
*
* @param rgb
* The new color.
*/
public void setColorValue(RGB rgb) {
fColorValue = rgb;
updateColorImage();
}
/**
* Set whether or not the button is enabled.
*
* @param state
* the enabled state.
*/
public void setEnabled(boolean state) {
getButton().setEnabled(state);
}
/**
* Update the image being displayed on the button using the current color
* setting.
*/
protected void updateColorImage() {
Display display = fButton.getDisplay();
GC gc = new GC(fImage);
gc.setForeground(display.getSystemColor(SWT.COLOR_BLACK));
gc.drawRectangle(0, 2, fExtent.x - 1, fExtent.y - 4);
if (fColor != null) {
fColor.dispose();
}
fColor = new Color(display, fColorValue);
gc.setBackground(fColor);
gc.fillRectangle(1, 3, fExtent.x - 2, fExtent.y - 5);
gc.dispose();
fButton.setImage(fImage);
}
/**
* Activate the editor for this selector. This causes the color selection
* dialog to appear and wait for user input.
*
* @since 3.2
*/
public void open() {
ColorDialog colorDialog = new ColorDialog(fButton.getShell());
colorDialog.setRGB(fColorValue);
RGB newColor = colorDialog.open();
if (newColor != null) {
RGB oldValue = fColorValue;
fColorValue = newColor;
final Object[] finalListeners = getListeners();
if (finalListeners.length > 0) {
PropertyChangeEvent pEvent = new PropertyChangeEvent(
this, PROP_COLORCHANGE, oldValue, newColor);
for (Object finalListener : finalListeners) {
IPropertyChangeListener listener = (IPropertyChangeListener) finalListener;
listener.propertyChange(pEvent);
}
}
updateColorImage();
}
}
}